A hydrogen-containing gas can be generated from a raw material through a reforming reaction. At the time, the raw material contains sulfur compounds. Since the sulfur compounds cause poisoning of a reforming catalyst, it is necessary to remove the sulfur compounds. The sulfur compounds can be removed by, for example, hydrodesulfurization in which a hydrogen gas and the raw material are mixed together.
Accordingly, part of the hydrogen-containing gas generated through the reforming reaction is returned to a raw material passage (hereinafter, such an operation is called “recycle”). In order to suppress water blockage in a recycle passage, there is proposed an apparatus configuration in which the recycle passage is provided with a condenser, and there is also another proposed apparatus configuration in which a hydrogen-containing gas that has passed through a condenser flows into the recycle passage (see Patent Literature 1, for example).